76 ASCAROIDEA 



minute knob. Oesophagus cylindroid, slightly expanded 

 behind. Tail terminates, in both sexes, in an expanded knob. 

 Male with two small spicules. Testis single, anterior, out- 

 stretched. Vulva at about the posterior fourth of the body. 

 Female genital tubes short, paired, opposed, outstretched. 



Hab. In galleries excavated under the sarcolemma of the 

 muscle -fibres of Frogs. 



Genotype : 31. iveismanni Eberth, 1863. 



Eberth, 1863, Zeitschr.f. wiss. Zool., xii, 530. 



Fam. 10. TRILOBIDAE Micoletzky, 1922. 



Free-living forms, mostly marine, with a distinct buccal 

 cavity without teeth. Oesophagus t3rpically without a true 

 muscular posterior bulb containing valves, but slightly ex- 

 panded behind. Reproductive organs simple. Sexes generally 

 distinct. Mostly oviparous, producing few and large eggs. 



Micoletzky (1922) divides this family into three subfamilies, 

 Trilobinae, Monhysterinae and Prismatolaiminae. The dis- 

 tinctions (based upon the form of the buccal capsule) between 

 these subfamilies are relative rather than absolute, and appear 

 to us too vague to justify the subdivision. 



1. Trilobus Bastian, 1865. 



Cuticle imstriated, often with bristles. No lateral alae. 

 Head not distinct, with a crow^a of stiff bristles, often in pairs. 

 Lateral organs mostly unknown. Buccal capsule cup- or 

 funnel-shaped, usually without teeth or local thickenings, its 

 dorsal wall not jointed. Oesophagus with tooth-like processes 

 near the anterior end but not immediately comiected with the 

 buccal capsule, and swollen posteriorly, but without bulb. 

 Caudal end of male with preanal papillae and without postanal 

 papillae. Two spicules and an accessory piece present. Testes 

 paired. Female genital tubes paired, opposed, reflexed. 

 Eggs relatively numerous. Caudal glands present. Spinneret 

 present or absent. 



Hab. Marine, fresh-water, or in sand or soil. 

 Genotyjje : T. gracilis Bastian, 1865. 



Bastian, 1865, Trans. Linn. Soc. London, xxv, 93, 99 ; 

 Micoletzky, 1922, Arch. f. Naturg., Abt. A, Ixxxvii, 186. 



Micoletzky (1922) divides the genus Trilobus into the sub- 

 genera Trilobus and Paratrilobus. The characters mentioned 

 in the diagnoses of these subgenera appear to justify their 

 separation as distinct genera. 



